https://en.wiktionary.org/w/index.php?title=put_down&oldid=63914349 https://en.wiktionary.org/w/index.php?title=put_down&oldid=6... 4th definition: (euphemisti

https://en.wiktionary.org/w/index.php?title=put_down&oldid=63914349 https://en.wiktionary.org/w/index.php?title=put_down&oldid=6... 4th definition: (euphemistic) To euthanize (an animal). I'd say it's not out of question that this could be applied to people as well.